Yet on every NFL defense, there are role players that perform a crucial function toward the success of the unit. These guys typically go relatively unnoticed for their critical contributions.

On Chicago's defense, the player who contributes the most yet gets the least amount of publicity is nickelback D.J. Moore. Tillman and Jennings are the starters, thus receiving most of the snaps, but neither has as much impact as Moore on a per-play basis.

CB D.J. MooreRob Grabowski/US Presswire

According to Pro Football Focus (PFF), Moore was on the field for 504 snaps last season, less than half of both Tillman (1,104) and Jennings (1,028). Yet Moore led the team with four interceptions. Opposing quarterbacks had a 60.9 rating when throwing to players Moore was covering, less than Tillman (73.5) and Jennings (68.8).

Additionally, Moore missed only two tackles all season and did not give up a single touchdown.

His contributions in the passing game should not be diminished due to his part-time status. Today's NFL becomes pass happier by the season. Three- and four-receiver sets are the norm. Green Bay's receivers, from top to bottom, are all a handful to cover, meaning the Bears must have a solid No. 3 cornerback if they're going to have any chance of shutting down the Packers' passing attack.

So while Moore may not be on the field for every snap, his job on passing downs is as important as anyone's on the team. Slot receivers can be just as dangerous as those out wide, meaning every NFL team needs a quality slot corner.

On top of his coverage ability, Moore also excels as a blitzer. PFF recently published its 2011 Pass Rushing Productivity (PRP) numbers for defensive backs. The formula is simple:

Basically, they look at every snap during which a defensive backs rushes the quarterback and grades their effectiveness. Moore rushed the passer 39 times last season and had eight total pressures, for a PRP of 15.38, eighth best amongst all defensive backs in the NFL last year. In 2010, Moore was also Top 10 in PRP.

Yet don't expect anyone to unseat Moore, who has been a consistent asset at nickelback. His ability in coverage, as well as a pass rusher, is unmatched on the team. For as long as Moore is in the slot, Chicago will be well-prepared against the multiple-receiver sets that permeate today's NFL.

Jeremy Stoltz is Publisher of Bear Report magazine and BearReport.com and a member of the Pro Football Writers of America. To read him every day, visit BearReport.com and become a Chicago Bears insider.